[PATCH AUTOSEL 4.19 71/81] netfilter: nf_tables: add missing ->release_ops() in error path of newrule()

From: Sasha Levin
Date: Tue May 07 2019 - 01:56:52 EST


From: Taehee Yoo <ap420073@xxxxxxxxx>

[ Upstream commit b25a31bf0ca091aa8bdb9ab329b0226257568bbe ]

->release_ops() callback releases resources and this is used in error path.
If nf_tables_newrule() fails after ->select_ops(), it should release
resources. but it can not call ->destroy() because that should be called
after ->init().
At this point, ->release_ops() should be used for releasing resources.

Test commands:
modprobe -rv xt_tcpudp
iptables-nft -I INPUT -m tcp <-- error command
lsmod

Result:
Module Size Used by
xt_tcpudp 20480 2 <-- it should be 0

Fixes: b8e204006340 ("netfilter: nft_compat: use .release_ops and remove list of extension")
Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index ef7ff13a7b99..ebfcfe1dcbdb 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2719,8 +2719,11 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
nf_tables_rule_release(&ctx, rule);
err1:
for (i = 0; i < n; i++) {
- if (info[i].ops != NULL)
+ if (info[i].ops) {
module_put(info[i].ops->type->owner);
+ if (info[i].ops->type->release_ops)
+ info[i].ops->type->release_ops(info[i].ops);
+ }
}
kvfree(info);
return err;
--
2.20.1